Update install_remnawave.sh

fix function extract_domain

Author: eGamesAPI

install_remnawave.sh

@@ -2948,7 +2948,16 @@ install_packages() {
 
 extract_domain() {
     local SUBDOMAIN=$1
-    echo "$SUBDOMAIN" | awk -F'.' '{if (NF > 2) {print $(NF-1)"."$NF} else {print $0}}'
+    echo "$SUBDOMAIN" | awk -F'.' '
+    {
+        if (NF == 3) {
+            print $(NF-1)"."$NF
+        } else if (NF > 3) {
+            print $(NF-2)"."$(NF-1)"."$NF
+        } else {
+            print $0
+        }
+    }'
 }
 
 check_domain() {
@@ -5566,4 +5575,4 @@ case $OPTION in
         exit 1
         ;;
 esac
-exit 0
+exit 0